The present invention relates to an electronic musical instrument having an automatic accompaniment mode.
A certain conventional electronic musical instrument of the automatic accompaniment type may have a particular function called "variation" such that a player can set and select a desired rhythm pattern every one or more measures or part of each measure during the course of continuous manual performance of a given music composition having a specific rhythm style. One rhythm style such as rock'n'roll or waltz may contain typically six variation rhythm patterns, i.e., normal pattern, bridge pattern, introduction pattern, ending pattern and two fill-in patterns (one of which shifts to normal pattern and another of which shifts to bridge pattern after fill-in pattern). During the course of manual performance with the aid of automatic accompaniment of a rhythm part with or without an auto-bass-chord (hereinafter, ABC) part containing bass and chord tones, the above noted variation rhythm patterns are suitably switched to change music mood, thereby realizing rich and full performance while modulating the music composition.
The normal pattern represents a basic pattern of a given rhythm style. The bridge pattern has a somewhat different impression than the normal pattern, and is effective when used in a climax period of the music composition. The introduction pattern is adopted to a given music style to enable a natural performance start of the music composition. The ending pattern is adopted to a given music style to enable a natural performance ending to terminate the rhythm accompaniment. The fill-in pattern is a somewhat irregular pattern different than those of the normal pattern and the bridge pattern, and is selected temporarily to impart a rhythm variation to the music composition. In some applications of the above mentioned "variation" method, the chord and bass patterns may be separately varied while the rhythm pattern is unchanged.
In the conventional electronic musical instrument, a timbre of musical sounds may be also switched during the course of manual performance such that, for example, piano sound can be switched to guitar sound or organ sound. Such timbre change is effected conventionally by either of the following two methods. A first method utilizes a plurality of timbre selecting switches provided correspondingly to a plurality of timbres representative of piano, guitar, organ and so on. These timbre selecting switches are manually operated to select instantly a desired timbre. A second method utilizes a registration function such that the electronic musical instrument is provided with a memory for provisionally registering a setting state of various buttons, levers and volume wheels on an operating panel as one group (which is called "registration"). The setting state of timbre etc. is provisionally stored in the memory as a part of each "registration". A particular registration is selected by operating a corresponding registration switch to effect the change in timbre etc.
In the conventional electronic musical instrument, it is desired to change the timbre concurrently with switching of the rhythm patterns during the course of manual performance along with automatic rhythm accompaniment with or without ABC, in order to further modify the music composition to effectively improve the quality of the performance. However, in practical terms, it is difficult to change the timbre simultaneously with a transition timing of the different rhythm patterns during the course of manual performance along with the automatic rhythm accompaniment. For example, with regard to the above mentioned first prior art, precedingly a rhythm selecting switch is operated during the manual performance, and then succeedingly a timbre selecting switch must be actuated while timing a transition moment from one variation rhythm pattern to another variation rhythm pattern. However, double manipulation of the two separate selecting switches is practically complicated in the middle of manual performance. Moreover, it is quite difficult to timely actuate the timbre selecting switch at the transition moment of variation rhythm patterns. Namely, the transition occurrence of variation rhythm patterns is not always fixed. For example, in the case of the ending pattern, when an ending switch is actuated to select the ending pattern within a first half period of one measure, a current rhythm pattern is instantly switched to the selected ending pattern. On the other hand, where the ending switch is actuated within a second half period of one measure, the ending pattern is initiated from a top of a next measure. Moreover, if all fingers of both hands are working on a keyboard incidentally at a just timing, a selecting switch cannot be timely addressed, thereby missing the just timing.
With regard to the above-mentioned second prior art, it may be possible to select either of a non-temporary variation rhythm pattern and a timbre by operation of one registration switch. However, normally temporary variation rhythm patterns such as the fill-in pattern and ending pattern etc. are not involved in "registration", and therefore they cannot be registered. Thus, it is impossible to effect concurrent switching of the timbre with these fill-in and ending patterns.